The object of this study was to conduct a preliminary investigation of newly developed corrosion inhibitors and inhibitor combinations for use in automotive coolants. Bench corrosion tests were conducted on the following inhibitors in water and ethylene glycol/water solutions: sodium tetraborate/ propylene glycol condensate, the double condensate of sodium tetraborate with propylene glycol and butynediol, and Specification 0-1-490 inhibitor modified by adding disodium phosphate and increasing the mercaptobenzothiazole content. Many combinations of these inhibitors performed satisfactorily in the bench corrosion tests. Dynamometer tests and field tests are warranted.